Which among the following functional groups is reduced by diborane?

Step-by-step solution

Diborane ( B₂ H₆ ) reduces the following functional groups: Esters ( -COOR ) are reduced to primary alcohols: RCOOR' B₂ H₆ RCH₂ OH + R'OH . Carboxylic acids ( -COOH ) are reduced to primary alcohols: RCOOH B₂ H₆ RCH₂ OH . Diborane is particularly useful for selective reduction of carboxylic acids. Nitro groups ( -NO₂ ) are reduced to primary amines: RNO₂ B₂ H₆ RNH₂ . Alkyl halides ( -X ) are unreactive toward diborane under typical conditions. Therefore, options A, B, and C are reduced by diborane. A, B, C